c# - 不能将第二个枚举值转换为 int？

Question

我不明白这个。我能够将我的第一个枚举值转换为 int 而不是第二个？

public enum PayPalTransactionType
{
    Authorization = 0, // Debit
    Capture = 1, // Credit
    Refund = 2,
    Void = 3
}

public string GetPayPalTransCode(PayPalServiceBase.PayPalTransactionType payPalTransactionType)
{
    string actionCode = string.Empty;

    switch (payPalTransactionType)
    {
        case (int)PayPalServiceBase.PayPalTransactionType.Authorization:
            actionCode = "Debit";
            break;
        case (int)PayPalServiceBase.PayPalTransactionType.Capture:
            actionCode = "Credit";
            break;
    }

    return actionCode;
}

在我的第二个案例陈述中，我得到了这个转换错误:

Cannot implicitly convert type int to PayPalTransactionType. An explicit conversion exists (are you missing a cast?)

Answer 1

您为什么首先尝试施法？只需将其保留为枚举值即可:

public string GetPayPalTransCode
    (PayPalServiceBase.PayPalTransactionType payPalTransactionType)
{
    string actionCode = string.Empty;

    switch (payPalTransactionType)
    {
        case PayPalServiceBase.PayPalTransactionType.Authorization:
            actionCode = "Debit";
            break;
        case PayPalServiceBase.PayPalTransactionType.Capture:
            actionCode = "Credit";
            break;
    }

    return actionCode;
}

此外，对于无法识别的代码，我有一个明确的默认操作，直接返回:

public string GetPayPalTransCode
    (PayPalServiceBase.PayPalTransactionType payPalTransactionType)
{
    switch (payPalTransactionType)
    {
        case PayPalServiceBase.PayPalTransactionType.Authorization:
            return "Debit";
        case PayPalServiceBase.PayPalTransactionType.Capture:
            return "Credit";
        default:
            return ""; // Or throw an exception if this represents an error
    }
}

或者，您可以使用 Dictionary<PayPalTransactionType, string> .